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(No Model.)

J. W. HENDERSON. ELECTRICAL INDICATOR.

No. 472,500 Patented Apr. 5, 1892.

T INVENTOR UNITED STATES PATENT OFFICE.

JOHN WV. HENDERSON, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO THE.VVHARTON RAILROAD SIVITCH COMPANY, OF SAME PLACE.

ELECTRICAL INDICATOR.

SPECIFICATION forming part of Letters Patent No. 472,500, dated April 5,1892. Application filed November 13, 1885. Serial No. 182.672. (Nomodel.)

To all whom it may concern.-

Be it known that I, JOHN W. HENDERSON, of the city and county ofPhiladelphia, and State of Pennsylvania, haveinvented an Improvement inElectrical Indicators or Detectors, of which the following is aspecification.

My invention has reference to electrical indicators; andit consists incertain impr'ovemen ts by which, through the aid of electricity, thevarious portions of a distant-moving object may be automaticallyindicated, all of which is fully set forth in the followingspecification, and shown in the accompanying drawings, which form partthereofi This invention is excellently adapted to detecting whether adistant railroad-signal is fully raised or lowered or is in anintermediate position, as is specified in my application filed January2, 1884, and Serial No. 116,200, patented December S,1885,N0.33l,879.The advantage of this is evident when we consider that inrailroad-signals, particularly those at long distance from theoperating-station, the rods or cables therefor, through contraction orexpansion or defective working, are varied to fully raise or lower thesaid signal, and the engineer on the train is therefore unable todetermine whether it means safety or danger. With this detectingapparatus, however, if the signal fails to come home when being raisedor lowered an automatic alarm is rung and continues to ring until thesaid signal is fully raised or lowered, and whichever position is thusassumed is clearly denoted by the pointer on the indicator. The sameinvention is also applicable to switches, doors, or any other objectwhich should move between two points.

In the drawings, Figure 1 is an elevation of the upper part of arailway-signal post and its arm and shows its connection with theelectric detector or indicator. Fig. 2 is a sectional elevation of theelectric detector or indicator, and Figs. 3 and 4: are modified forms ofconstruction of the electric indicator or detector.

M is the signalarm or semaphore, which is pivoted to the vertical postm, and is provided with the red-glass bulls-eye M to warn danger in thenight-time, and is adapted to swing in front of the lantern N, securedto the top of the post. The arm M, when brought to its two extremepositions, comes in contact with contact-springs R R, connected by wiresr r with an indicator S in the operators house. Thepivot m of the arm Mis also connected with said indicator S by a wire r and has a battery Rlocated therein. If desired, this line r may be made a ground-wire.

The indicator may be constructed as follows: Referring to Fig. 2, thewires r r are in circuit with magnets S S between the poles of which isan armature S connected witha pivoted band or pointer S, which, when inthe position shown in said figure, indicates that the arm M is neitherup nor down and the signal is eitherin a state of transition or workingdefectively; but when attracted by electro-magnet S indicates that thearm is down, and when attracted by electro-magnet S indicates that it isup. The wires r r are also in circuit with electro-magnetsT T, and arethen connected together and unite with the wire T The armatures '1 ofthe electromagnets T T are pressed against contactscrews T hyspringstwhen no current passes, and this closes a local circuit by wire U,through battery U and alarm U If desired, the battery U may be dispensedwith and the circuit U derive its current from battery R WVhen the arm Mis up, as shown in Fig. 1, the circuit is closed through wire r andelectro-magnets S and T, the former of which attracts the armature Scausing the needle or pointer S to point to red, and the latter to breakthe local circuit U by attracting its armature T When the arm is down,the same elfect is produced, but by magnets S and T, and the pointer Spoints to white. In the act of raising or lowering the arm the alarm Ushould ring. If it does not the device is out of order.

In place of the construction of indicator shown in Fig. 2 that shown inFig. 4 may be used, in which the magnets T T are dispensed with andspring-contacts t 15 used for the 10- cal circuit U, or that shown inFig. 3 may be used, in which the magnets T T are also dispensed with,but the armatures T worked by the magnets S S Having now described myinventiomwhat I claim as new, and desire to secure by Letters Patent,is-

1. In a railroad-signal the combination of the signal-arm M, contacts RR, circuits 1' 'r'r hattery R and an electric detector S to in dicatethe position of said arm M and sound an alarm While said arm is passingfrom one of its extreme positions to the other, the said detector andalarm consisting of electromagnets S S, armature S, pointer S, contactsT local circuits U, and alarm U substantially as and for the purposespecified.

2. A detector or indicator for indicating the two extremes or theintermediate position of a moving object, consisting of two electriccircuits, each provided with an electro-magnet adapted to attract thearmature of a needle JOHN W. HENDERSON.

Witnesses:

R. M. I IUNTER, E. M. BRECKINREED.

